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* [PATCH v33 07/11] pg_ls_*dir to return all the metadata from pg_stat_file..
@ 2020-03-10 02:56 Justin Pryzby <[email protected]>
0 siblings, 0 replies; 3+ messages in thread
From: Justin Pryzby @ 2020-03-10 02:56 UTC (permalink / raw)
..but it doesn't seem worth factoring out the common bits, since stat_file
doesn't return a name, so all the field numbers are off by one.
NOTE, the atime is now shown where the mtime used to be.
Need catversion bump
---
doc/src/sgml/func.sgml | 34 ++++++---
src/backend/utils/adt/genfile.c | 72 +++++++++-----------
src/include/catalog/pg_proc.dat | 42 ++++++------
src/test/regress/expected/misc_functions.out | 40 +++++------
src/test/regress/expected/tablespace.out | 8 +--
5 files changed, 102 insertions(+), 94 deletions(-)
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 53909e68ba3..a9106f13eae 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25969,7 +25969,10 @@ postgres=# SELECT * FROM pg_walfile_name_offset(pg_stop_backup());
<returnvalue>setof record</returnvalue>
( <parameter>filename</parameter> <type>text</type>,
<parameter>size</parameter> <type>bigint</type>,
+ <parameter>access</parameter> <type>timestamp with time zone</type>,
<parameter>modification</parameter> <type>timestamp with time zone</type>,
+ <parameter>change</parameter> <type>timestamp with time zone</type>,
+ <parameter>creation</parameter> <type>timestamp with time zone</type>,
<parameter>isdir</parameter> <type>boolean</type> )
</para>
<para>
@@ -27351,13 +27354,16 @@ SELECT pg_size_pretty(sum(pg_relation_size(relid))) AS total_size
<returnvalue>setof record</returnvalue>
( <parameter>name</parameter> <type>text</type>,
<parameter>size</parameter> <type>bigint</type>,
+ <parameter>access</parameter> <type>timestamp with time zone</type>,
<parameter>modification</parameter> <type>timestamp with time zone</type>,
+ <parameter>change</parameter> <type>timestamp with time zone</type>,
+ <parameter>creation</parameter> <type>timestamp with time zone</type>,
<parameter>isdir</parameter> <type>boolean</type> )
</para>
<para>
For each file in the server's log directory,
- return the file's name, size, last modification time (mtime), and a boolean
- indicating if the file is a directory.
+ return the file's name, along with the metadata columns returned by
+ <function>pg_stat_file</function>.
Filenames beginning with a dot and special file types are excluded.
</para>
<para>
@@ -27376,13 +27382,16 @@ SELECT pg_size_pretty(sum(pg_relation_size(relid))) AS total_size
<returnvalue>setof record</returnvalue>
( <parameter>name</parameter> <type>text</type>,
<parameter>size</parameter> <type>bigint</type>,
+ <parameter>access</parameter> <type>timestamp with time zone</type>,
<parameter>modification</parameter> <type>timestamp with time zone</type>,
+ <parameter>change</parameter> <type>timestamp with time zone</type>,
+ <parameter>creation</parameter> <type>timestamp with time zone</type>,
<parameter>isdir</parameter> <type>boolean</type> )
</para>
<para>
For each file in the server's write-ahead log (WAL) directory, list the
- file's name, size, last modification time (mtime), and a boolean
- indicating if the file is a directory.
+ file's name along with the metadata columns returned by
+ <function>pg_stat_file</function>.
Filenames beginning with a dot and special files types are excluded.
</para>
<para>
@@ -27474,14 +27483,17 @@ SELECT pg_size_pretty(sum(pg_relation_size(relid))) AS total_size
<returnvalue>setof record</returnvalue>
( <parameter>name</parameter> <type>text</type>,
<parameter>size</parameter> <type>bigint</type>,
+ <parameter>access</parameter> <type>timestamp with time zone</type>,
<parameter>modification</parameter> <type>timestamp with time zone</type>,
+ <parameter>change</parameter> <type>timestamp with time zone</type>,
+ <parameter>creation</parameter> <type>timestamp with time zone</type>,
<parameter>isdir</parameter> <type>boolean</type> )
</para>
<para>
For each file in the server's WAL archive status directory
- (<filename>pg_wal/archive_status</filename>), list the file's
- name, size, last modification time (mtime), and a boolean indicating if
- the file is a directory.
+ (<filename>pg_wal/archive_status</filename>), list the file's name
+ along with the metadata columns returned by
+ <function>pg_stat_file</function>.
Filenames beginning with a dot and special file types are excluded.
</para>
<para>
@@ -27501,13 +27513,17 @@ SELECT pg_size_pretty(sum(pg_relation_size(relid))) AS total_size
<returnvalue>setof record</returnvalue>
( <parameter>name</parameter> <type>text</type>,
<parameter>size</parameter> <type>bigint</type>,
+ <parameter>access</parameter> <type>timestamp with time zone</type>,
<parameter>modification</parameter> <type>timestamp with time zone</type>,
+ <parameter>change</parameter> <type>timestamp with time zone</type>,
+ <parameter>creation</parameter> <type>timestamp with time zone</type>,
<parameter>isdir</parameter> <type>boolean</type> )
</para>
<para>
For each file in the temporary directory within the given
- <parameter>tablespace</parameter>, return the file's name, size, last
- modification time (mtime) and a boolean indicating if the file is a directory.
+ <parameter>tablespace</parameter>, list the file's name
+ along with the metadata columns returned by
+ <function>pg_stat_file</function>.
Directories are used for temporary files shared by parallel processes.
If <parameter>tablespace</parameter> is not provided, the
<literal>pg_default</literal> tablespace is examined.
diff --git a/src/backend/utils/adt/genfile.c b/src/backend/utils/adt/genfile.c
index e49a15aa279..847d031af60 100644
--- a/src/backend/utils/adt/genfile.c
+++ b/src/backend/utils/adt/genfile.c
@@ -37,6 +37,8 @@
#include "utils/syscache.h"
#include "utils/timestamp.h"
+static void values_from_stat(struct stat *fst, const char *path, Datum *values,
+ bool *nulls);
static Datum pg_ls_dir_files(FunctionCallInfo fcinfo, const char *dir, int flags);
#define LS_DIR_ISDIR (1<<0) /* Show column: isdir */
@@ -400,6 +402,28 @@ pg_read_binary_file_all(PG_FUNCTION_ARGS)
return pg_read_binary_file(fcinfo);
}
+/*
+ * Populate values and nulls from fst and path.
+ * Used for pg_stat_file() and pg_ls_dir_files()
+ * nulls is assumed to have been zerod.
+ */
+static void
+values_from_stat(struct stat *fst, const char *path, Datum *values, bool *nulls)
+{
+ values[0] = Int64GetDatum((int64) fst->st_size);
+ values[1] = TimestampTzGetDatum(time_t_to_timestamptz(fst->st_atime));
+ values[2] = TimestampTzGetDatum(time_t_to_timestamptz(fst->st_mtime));
+ /* Unix has file status change time, while Win32 has creation time */
+#if !defined(WIN32) && !defined(__CYGWIN__)
+ values[3] = TimestampTzGetDatum(time_t_to_timestamptz(fst->st_ctime));
+ nulls[4] = true;
+#else
+ nulls[3] = true;
+ values[4] = TimestampTzGetDatum(time_t_to_timestamptz(fst->st_ctime));
+#endif
+ values[5] = BoolGetDatum(S_ISDIR(fst->st_mode));
+}
+
/*
* stat a file
*/
@@ -410,7 +434,7 @@ pg_stat_file(PG_FUNCTION_ARGS)
char *filename;
struct stat fst;
Datum values[6];
- bool isnull[6];
+ bool nulls[6];
HeapTuple tuple;
TupleDesc tupdesc;
bool missing_ok = false;
@@ -450,27 +474,9 @@ pg_stat_file(PG_FUNCTION_ARGS)
"isdir", BOOLOID, -1, 0);
BlessTupleDesc(tupdesc);
- memset(isnull, false, sizeof(isnull));
-
- values[0] = Int64GetDatum((int64) fst.st_size);
- values[1] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_atime));
- values[2] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_mtime));
- /* Unix has file status change time, while Win32 has creation time */
-#if !defined(WIN32) && !defined(__CYGWIN__)
- values[3] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_ctime));
- isnull[4] = true;
-#else
- isnull[3] = true;
- values[4] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_ctime));
-#endif
- values[5] = BoolGetDatum(S_ISDIR(fst.st_mode));
-#ifdef WIN32
- /* Links should have isdir=false */
- if (pgwin32_is_junction(filename))
- values[5] = BoolGetDatum(false);
-#endif
-
- tuple = heap_form_tuple(tupdesc, values, isnull);
+ memset(nulls, false, sizeof(nulls));
+ values_from_stat(&fst, filename, values, nulls);
+ tuple = heap_form_tuple(tupdesc, values, nulls);
pfree(filename);
@@ -611,8 +617,8 @@ pg_ls_dir_files(FunctionCallInfo fcinfo, const char *dir, int flags)
while ((de = ReadDir(dirdesc, dir)) != NULL)
{
- Datum values[4];
- bool nulls[4];
+ Datum values[7];
+ bool nulls[7];
char path[MAXPGPATH * 2];
struct stat attrib;
@@ -651,24 +657,10 @@ pg_ls_dir_files(FunctionCallInfo fcinfo, const char *dir, int flags)
continue;
}
+ memset(nulls, false, sizeof(nulls));
values[0] = CStringGetTextDatum(de->d_name);
if (flags & LS_DIR_METADATA)
- {
- values[1] = Int64GetDatum((int64) attrib.st_size);
- values[2] = TimestampTzGetDatum(time_t_to_timestamptz(attrib.st_mtime));
- if (flags & LS_DIR_ISDIR)
- {
-#ifdef WIN32
- /* Links should have isdir=false */
- if (pgwin32_is_junction(path))
- values[3] = BoolGetDatum(false);
- else
-#endif
- values[3] = BoolGetDatum(S_ISDIR(attrib.st_mode));
- }
- }
-
- memset(nulls, 0, sizeof(nulls));
+ values_from_stat(&attrib, path, 1+values, 1+nulls);
tuplestore_putvalues(tupstore, tupdesc, values, nulls);
}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index c5bbae2408b..ee7793467d0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11615,63 +11615,63 @@
{ oid => '3353', descr => 'list files in the log directory',
proname => 'pg_ls_logdir', procost => '10', prorows => '20', proretset => 't',
provolatile => 'v', prorettype => 'record', proargtypes => '',
- proallargtypes => '{text,int8,timestamptz,bool}', proargmodes => '{o,o,o,o}',
- proargnames => '{name,size,modification,isdir}', prosrc => 'pg_ls_logdir' },
+ proallargtypes => '{text,int8,timestamptz,timestamptz,timestamptz,timestamptz,bool}', proargmodes => '{o,o,o,o,o,o,o}',
+ proargnames => '{name,size,access,modification,change,creation,isdir}', prosrc => 'pg_ls_logdir' },
{ oid => '3354', descr => 'list of files in the WAL directory',
proname => 'pg_ls_waldir', procost => '10', prorows => '20', proretset => 't',
provolatile => 'v', prorettype => 'record', proargtypes => '',
- proallargtypes => '{text,int8,timestamptz,bool}', proargmodes => '{o,o,o,o}',
- proargnames => '{name,size,modification,isdir}', prosrc => 'pg_ls_waldir' },
+ proallargtypes => '{text,int8,timestamptz,timestamptz,timestamptz,timestamptz,bool}', proargmodes => '{o,o,o,o,o,o,o}',
+ proargnames => '{name,size,access,modification,change,creation,isdir}', prosrc => 'pg_ls_waldir' },
{ oid => '5031', descr => 'list of files in the archive_status directory',
proname => 'pg_ls_archive_statusdir', procost => '10', prorows => '20',
proretset => 't', provolatile => 'v', prorettype => 'record',
- proargtypes => '', proallargtypes => '{text,int8,timestamptz,bool}',
- proargmodes => '{o,o,o,o}', proargnames => '{name,size,modification,isdir}',
+ proargtypes => '', proallargtypes => '{text,int8,timestamptz,timestamptz,timestamptz,timestamptz,bool}',
+ proargmodes => '{o,o,o,o,o,o,o}', proargnames => '{name,size,access,modification,change,creation,isdir}',
prosrc => 'pg_ls_archive_statusdir' },
{ oid => '5029', descr => 'list files in the pgsql_tmp directory',
proname => 'pg_ls_tmpdir', procost => '10', prorows => '20', proretset => 't',
provolatile => 'v', prorettype => 'record', proargtypes => '',
- proallargtypes => '{text,int8,timestamptz,bool}', proargmodes => '{o,o,o,o}',
- proargnames => '{name,size,modification,isdir}', prosrc => 'pg_ls_tmpdir_noargs' },
+ proallargtypes => '{text,int8,timestamptz,timestamptz,timestamptz,timestamptz,bool}', proargmodes => '{o,o,o,o,o,o,o}',
+ proargnames => '{name,size,access,modification,change,creation,isdir}', prosrc => 'pg_ls_tmpdir_noargs' },
{ oid => '5030', descr => 'list files in the pgsql_tmp directory',
proname => 'pg_ls_tmpdir', procost => '10', prorows => '20', proretset => 't',
provolatile => 'v', prorettype => 'record', proargtypes => 'oid',
- proallargtypes => '{oid,text,int8,timestamptz,bool}', proargmodes => '{i,o,o,o,o}',
- proargnames => '{tablespace,name,size,modification,isdir}',
+ proallargtypes => '{oid,text,int8,timestamptz,timestamptz,timestamptz,timestamptz,bool}', proargmodes => '{i,o,o,o,o,o,o,o}',
+ proargnames => '{tablespace,name,size,access,modification,change,creation,isdir}',
prosrc => 'pg_ls_tmpdir_1arg' },
{ oid => '9858',
descr => 'list of files in the pg_logical/snapshots directory',
proname => 'pg_ls_logicalsnapdir', procost => '10', prorows => '20',
proretset => 't', provolatile => 'v', prorettype => 'record',
- proargtypes => '', proallargtypes => '{text,int8,timestamptz,bool}',
- proargmodes => '{o,o,o,o}', proargnames => '{name,size,modification,isdir}',
+ proargtypes => '', proallargtypes => '{text,int8,timestamptz,timestamptz,timestamptz,timestamptz,bool}',
+ proargmodes => '{o,o,o,o,o,o,o}', proargnames => '{name,size,access,modification,change,creation,isdir}',
prosrc => 'pg_ls_logicalsnapdir' },
{ oid => '9859',
descr => 'list of files in the pg_logical/mappings directory',
proname => 'pg_ls_logicalmapdir', procost => '10', prorows => '20',
proretset => 't', provolatile => 'v', prorettype => 'record',
- proargtypes => '', proallargtypes => '{text,int8,timestamptz,bool}',
- proargmodes => '{o,o,o,o}', proargnames => '{name,size,modification,isdir}',
+ proargtypes => '', proallargtypes => '{text,int8,timestamptz,timestamptz,timestamptz,timestamptz,bool}',
+ proargmodes => '{o,o,o,o,o,o,o}', proargnames => '{name,size,access,modification,change,creation,isdir}',
prosrc => 'pg_ls_logicalmapdir' },
{ oid => '9860',
descr => 'list of files in the pg_replslot/slot_name directory',
proname => 'pg_ls_replslotdir', procost => '10', prorows => '20',
proretset => 't', provolatile => 'v', prorettype => 'record',
- proargtypes => 'text', proallargtypes => '{text,text,int8,timestamptz,bool}',
- proargmodes => '{i,o,o,o,o}',
- proargnames => '{slot_name,name,size,modification,isdir}',
+ proargtypes => 'text', proallargtypes => '{text,text,int8,timestamptz,timestamptz,timestamptz,timestamptz,bool}',
+ proargmodes => '{i,o,o,o,o,o,o,o}',
+ proargnames => '{slot_name,name,size,access,modification,change,creation,isdir}',
prosrc => 'pg_ls_replslotdir' },
{ oid => '8450', descr => 'list directory with metadata',
proname => 'pg_ls_dir_metadata', procost => '10', prorows => '20', proretset => 't',
provolatile => 'v', prorettype => 'record', proargtypes => 'text bool bool',
- proallargtypes => '{text,bool,bool,text,int8,timestamptz,bool}', proargmodes => '{i,i,i,o,o,o,o}',
- proargnames => '{dirname,missing_ok,include_dot_dirs,filename,size,modification,isdir}',
+ proallargtypes => '{text,bool,bool,text,int8,timestamptz,timestamptz,timestamptz,timestamptz,bool}', proargmodes => '{i,i,i,o,o,o,o,o,o,o}',
+ proargnames => '{dirname,missing_ok,include_dot_dirs,filename,size,access,modification,change,creation,isdir}',
prosrc => 'pg_ls_dir_metadata' },
{ oid => '8451', descr => 'list directory with metadata',
proname => 'pg_ls_dir_metadata', procost => '10', prorows => '20', proretset => 't',
provolatile => 'v', prorettype => 'record', proargtypes => 'text',
- proallargtypes => '{text,text,int8,timestamptz,bool}', proargmodes => '{i,o,o,o,o}',
- proargnames => '{dirname,filename,size,modification,isdir}',
+ proallargtypes => '{text,text,int8,timestamptz,timestamptz,timestamptz,timestamptz,bool}', proargmodes => '{i,o,o,o,o,o,o,o}',
+ proargnames => '{dirname,filename,size,access,modification,change,creation,isdir}',
prosrc => 'pg_ls_dir_metadata_1arg' },
# hash partitioning constraint function
diff --git a/src/test/regress/expected/misc_functions.out b/src/test/regress/expected/misc_functions.out
index 91b6dba70b9..0db07209cc9 100644
--- a/src/test/regress/expected/misc_functions.out
+++ b/src/test/regress/expected/misc_functions.out
@@ -206,8 +206,8 @@ select count(*) > 0 as ok from (select pg_ls_waldir()) ss;
-- Test not-run-to-completion cases.
select * from pg_ls_waldir() limit 0;
- name | size | modification | isdir
-------+------+--------------+-------
+ name | size | access | modification | change | creation | isdir
+------+------+--------+--------------+--------+----------+-------
(0 rows)
select count(*) > 0 as ok from (select * from pg_ls_waldir() limit 1) ss;
@@ -270,38 +270,38 @@ select pg_ls_dir('does not exist'); -- fails with missingok=false
ERROR: could not open directory "does not exist": No such file or directory
-- Check that expected columns are present
select * from pg_ls_archive_statusdir() limit 0;
- name | size | modification | isdir
-------+------+--------------+-------
+ name | size | access | modification | change | creation | isdir
+------+------+--------+--------------+--------+----------+-------
(0 rows)
select * from pg_ls_logdir() limit 0;
- name | size | modification | isdir
-------+------+--------------+-------
+ name | size | access | modification | change | creation | isdir
+------+------+--------+--------------+--------+----------+-------
(0 rows)
select * from pg_ls_logicalmapdir() limit 0;
- name | size | modification | isdir
-------+------+--------------+-------
+ name | size | access | modification | change | creation | isdir
+------+------+--------+--------------+--------+----------+-------
(0 rows)
select * from pg_ls_logicalsnapdir() limit 0;
- name | size | modification | isdir
-------+------+--------------+-------
+ name | size | access | modification | change | creation | isdir
+------+------+--------+--------------+--------+----------+-------
(0 rows)
select * from pg_ls_replslotdir('') limit 0;
- name | size | modification | isdir
-------+------+--------------+-------
+ name | size | access | modification | change | creation | isdir
+------+------+--------+--------------+--------+----------+-------
(0 rows)
select * from pg_ls_tmpdir() limit 0;
- name | size | modification | isdir
-------+------+--------------+-------
+ name | size | access | modification | change | creation | isdir
+------+------+--------+--------------+--------+----------+-------
(0 rows)
select * from pg_ls_waldir() limit 0;
- name | size | modification | isdir
-------+------+--------------+-------
+ name | size | access | modification | change | creation | isdir
+------+------+--------+--------------+--------+----------+-------
(0 rows)
select * from pg_stat_file('.') limit 0;
@@ -312,8 +312,8 @@ select * from pg_stat_file('.') limit 0;
-- This tests the missing_ok parameter, which causes pg_ls_tmpdir to succeed even if the tmpdir doesn't exist yet
-- The name='' condition is never true, so the function runs to completion but returns zero rows.
select * from pg_ls_tmpdir() where name='Does not exist';
- name | size | modification | isdir
-------+------+--------------+-------
+ name | size | access | modification | change | creation | isdir
+------+------+--------+--------------+--------+----------+-------
(0 rows)
select filename, isdir from pg_ls_dir_metadata('.') where filename='.';
@@ -329,8 +329,8 @@ select filename, isdir from pg_ls_dir_metadata('.', false, false) where filename
-- Check that expected columns are present
select * from pg_ls_dir_metadata('.') limit 0;
- filename | size | modification | isdir
-----------+------+--------------+-------
+ filename | size | access | modification | change | creation | isdir
+----------+------+--------+--------------+--------+----------+-------
(0 rows)
--
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index 50a3a13fbea..b01ca30c7ab 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -28,15 +28,15 @@ CREATE TABLESPACE regress_tblspace LOCATION '';
-- The name='' condition is never true, so the function runs to completion but returns zero rows.
-- The query is written to ERROR if the tablespace doesn't exist, rather than silently failing to call pg_ls_tmpdir()
SELECT c.* FROM (SELECT oid FROM pg_tablespace b WHERE b.spcname='regress_tblspace' UNION SELECT 0 ORDER BY 1 DESC LIMIT 1) AS b , pg_ls_tmpdir(oid) AS c WHERE c.name='Does not exist';
- name | size | modification | isdir
-------+------+--------------+-------
+ name | size | access | modification | change | creation | isdir
+------+------+--------+--------------+--------+----------+-------
(0 rows)
-- This tests the missing_ok parameter. If that's not functioning, this would ERROR if the logdir doesn't exist yet.
-- The name='' condition is never true, so the function runs to completion but returns zero rows.
SELECT * FROM pg_ls_logdir() WHERE name='Does not exist';
- name | size | modification | isdir
-------+------+--------------+-------
+ name | size | access | modification | change | creation | isdir
+------+------+--------+--------------+--------+----------+-------
(0 rows)
-- try setting and resetting some properties for the new tablespace
--
2.17.1
--9CzcV6dAFIr7O1Ie
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v33-0008-pg_stat_file-and-pg_ls_dir_-to-use-lstat.patch"
^ permalink raw reply [nested|flat] 3+ messages in thread
* Question on partition pruning involving stable operator: timestamptz_ge_date
@ 2022-01-27 01:28 TAO TANG <[email protected]>
0 siblings, 1 reply; 3+ messages in thread
From: TAO TANG @ 2022-01-27 01:28 UTC (permalink / raw)
To: [email protected]
Hi,
I tested the following case in PostgreSQL master:58e2e6
the partition table created:
create table tbl_dts (dts timestamp with time zone not null) partition
by range(dts);
create table tbl_dts_1 partition of tbl_dts for values from
('2021-07-02') to ('2021-08-01');
create table tbl_dts_2 partition of tbl_dts for values from
('2021-08-02') to ('2021-09-01');
create table tbl_dts_3 partition of tbl_dts for values from
('2021-09-02') to ('2021-10-01');
create table tbl_dts_4 partition of tbl_dts for values from
('2021-10-02') to ('2021-11-01');
and the query:
explain select * from tbl_dts where dts between '2022-01-20'::date and
'2022-01-26'::date;
QUERY PLAN
---------------------------------------------
Append (cost=0.00..175.82 rows=44 width=8)
Subplans Removed: 4
(2 rows)
the plan shows all the partitions are pruned, but in gdb tracing, it shows
that
the pruning happens in ExecInitAppend, and during planning stage pg does not
prune any partitions. this is because in function
match_clause_to_partition_key
do not handle the case for STABLE operator:
if (op_volatile(opno) != PROVOLATILE_IMMUTABLE)
{
context->has_mutable_op = true;
/*
* When pruning in the planner, we cannot prune with mutable
* operators.
*/
if (context->target == PARTTARGET_PLANNER)
return PARTCLAUSE_UNSUPPORTED;
}
the procs for timestamptz compare with date are STABLE:
proname | provolatile
----------------------+-------------
timestamptz_lt_date | s
timestamptz_le_date | s
timestamptz_eq_date | s
timestamptz_gt_date | s
timestamptz_ge_date | s
timestamptz_ne_date | s
timestamptz_cmp_date | s
(7 rows)
but in ExecInitAppend call perform_pruning_base_step which do not consider
the STABLE
property of the cmpfn.
so I have serveral questions:
1) why in planning the function volatility is considered but not in
execInitAppend;
2) why timestamptz_xxx_date is STABLE not IMMUTABLE;
thanks.
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Question on partition pruning involving stable operator: timestamptz_ge_date
@ 2022-01-27 02:11 Amit Langote <[email protected]>
parent: TAO TANG <[email protected]>
0 siblings, 0 replies; 3+ messages in thread
From: Amit Langote @ 2022-01-27 02:11 UTC (permalink / raw)
To: TAO TANG <[email protected]>; +Cc: [email protected]
Hi,
On Thu, Jan 27, 2022 at 10:28 AM TAO TANG <[email protected]> wrote:
> the plan shows all the partitions are pruned, but in gdb tracing, it shows that
> the pruning happens in ExecInitAppend, and during planning stage pg does not
> prune any partitions. this is because in function match_clause_to_partition_key
> do not handle the case for STABLE operator:
>
> if (op_volatile(opno) != PROVOLATILE_IMMUTABLE)
> {
> context->has_mutable_op = true;
>
> /*
> * When pruning in the planner, we cannot prune with mutable
> * operators.
> */
> if (context->target == PARTTARGET_PLANNER)
> return PARTCLAUSE_UNSUPPORTED;
> }
>
> the procs for timestamptz compare with date are STABLE:
>
> proname | provolatile
> ----------------------+-------------
> timestamptz_lt_date | s
> timestamptz_le_date | s
> timestamptz_eq_date | s
> timestamptz_gt_date | s
> timestamptz_ge_date | s
> timestamptz_ne_date | s
> timestamptz_cmp_date | s
> (7 rows)
>
> but in ExecInitAppend call perform_pruning_base_step which do not consider the STABLE
> property of the cmpfn.
>
> so I have serveral questions:
> 1) why in planning the function volatility is considered but not in execInitAppend;
The value of a STABLE expression can change based on runtime
parameters, so while it is guaranteed to remain the same during a
particular execution of a plan in which it is contained, it can change
across multiple executions of that plan (if it is cached, for
example). So the planner cannot assume a particular value of such
expressions when choosing partitions to add to the plan, because each
execution of the plan (each may run in a separate transaction) can
produce different values. ExecInitAppend(), on the other hand, can
assume a particular value when choosing partitions to initialize,
because the value is fixed for a particular execution during which it
runs.
> 2) why timestamptz_xxx_date is STABLE not IMMUTABLE;
Because calculations involving timestamptz values can produce
different results dependkng on volatile settings like timezone,
datestyle, etc.
--
Amit Langote
EDB: http://www.enterprisedb.com
^ permalink raw reply [nested|flat] 3+ messages in thread
end of thread, other threads:[~2022-01-27 02:11 UTC | newest]
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2020-03-10 02:56 [PATCH v33 07/11] pg_ls_*dir to return all the metadata from pg_stat_file.. Justin Pryzby <[email protected]>
2022-01-27 01:28 Question on partition pruning involving stable operator: timestamptz_ge_date TAO TANG <[email protected]>
2022-01-27 02:11 ` Re: Question on partition pruning involving stable operator: timestamptz_ge_date Amit Langote <[email protected]>
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